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The .ogg file format is a type of audio file that makes use of open source Ogg Vorbis compression. It is supported by devices such as Archos and Samsung but is not supported by Apple iOS devices. The .ogg format has been utilised for the provision of streaming audio. The file format is unlikely at present to take a dominant share of the digital music market due to the synonymous nature of MP3 with digital audio.

The .ogg format is actually a container that potentially allows for different streams of audio, video and metadata. Ogg Vorbis is the compression format. It provides medium to high quality audio at between 16 and 128 kbps/channel and is better quality sound than mp3. The OGG file type is a lossy codec which means that data is discarded as part of the compression technique, resulting in a smaller file size. Ogg files are optimised for music files, but will still be of acceptable quality for speech only files.

Developed by the Signal Processing Group at Microsoft, the WMA file format is part of the Windows Media framework and was first released commercially in 1999, with support for playback of WMA encoded files as part of Windows Media Player. Creation of WMA files did not come until Windows Media Player version 7. The original codec was targeted as a direct competitor to the MP3 and RealAudio formats, and has achieved a broad level of adoption thanks to support for playback on numerous DVD players, Nokia mobile handsets and Playstation portable devices.

In almost all circumstances WMA files are part of the Advanced Systems Format (ASF) container, a proprietary container format developed by Microsoft for both digital video and digital audio. Every WMA file contains an audio track encoded in one of four mutually distinct codecs - WMA, WMA Voice, WMA Lossless or WMA Pro - WMA is the most commonly found of the four, but is a lossy codec, with the ability to encode audio signals sampled at up to 48 kHz. WMA Pro is an improved version, allowing sampling up to 96 kHz, but has achieved little hardware and software support. WMA Lossless is designed to compress audio signals with no loss of quality from the original source (up to 96 kHz) and is used in some Windows Mobile devices as well as the Logitech Squeezebox Touch. Finally, WMA Voice is a lossy codec optimized for low-bandwith voice playback applications, with mono sampling support up to 22.05 kHz - it is perhaps most well known for being used by the BBC World service for streaming Internet radio.